1. Field of Invention
The present invention relates to the pathogen reducing arts. It applies particularly to microbial decontamination of uncooked food product, and will be described with particular reference thereto.
2. Background
Prevention of food poisoning is of paramount importance in the food processing industry, whether for human consumption or for pet consumption. Concern for food safety has lead most countries to regulate the food industry heavily to minimize public health risks. Despite these efforts, food poisoning still occurs in humans and in pets. Many instances of food poisoning are attributed to bacteria, such as Salmonella, Clostridium, and Staphylococcus, among others. Furthermore, recent failures in food safety protocol in pet food processing plants in China resulted in the unnecessary food poisoning of hundreds of animals.
Application of heat to the food is commonly used to reduce pathogens in food. However, heat can damage food. Also, certain pets may not be able to obtain the proper nutrition from cooked foods. Also, flavor and texture may be altered through the application of heat.
An alternative to heat treatment is the use of antimicrobial ingredients, such as potassium sorbate, propionates, or benzoates are often added to foods to protect against microbial spoilage. However these compounds adversely affect the flavor of products. Furthermore, the long term effect of these compounds on humans and animals is not entirely known.
High pressure processing (HPP) has been investigated as a method for preservation of foods. In such processing, high hydrostatic pressure without thermal treatment is applied to a food product to reduce its microbial load. For example, U.S. Pat. No. 6,635,223 discloses methods for inactivating microorganisms in products packed in a flexible container using high pressure (500 to 8000 bar). Similarly, the published U.S. patent application of Turek et al. having Ser. No. 10/903,016 discloses a method of reducing pathogens using high pressure treatment of food product of approximately 300 MPa. Sufficiently high pressure conditions may destabilize the cell membranes of food borne illness causing microorganisms, thereby reducing their survivability and activity without causing damage to the food. Thus, HPP allows the pathogens to be reduced without there being any heat or chemical related changes to the food.
Furthermore, additional processing may be required for the food product which may have the possibility of subjecting food to pathogens after high pressure treatment. For example, dicing or grinding may be needed for optimal texture of the end product.
It would therefore be desirable to enhance the effectiveness of high pressure treatment of food by using additional means for reducing pathogens that do not cook or chemically treat the food.
There remains a need for a method for the reduction of pathogens in food for humans or animals that does not heat or chemically treat the food. The present invention fulfills this objective, as well as other needs and objectives, as will be apparent from the following description of the present invention.